"This is a time for unity," House Speaker John Boehner, R-Ohio, said Thursday.

WASHINGTON — House Majority Leader Eric Cantor's decision to relinquish his leadership post after Tuesday's primary defeat has sparked a rare mid-session leadership battle among House Republicans, pitting lawmakers against one another in an effort to redefine the direction of the party before this year's elections.

Some GOP lawmakers would like to see a roster of more ardent conservatives in leadership, but their hopes were largely dashed after Financial Services Chairman Jeb Hensarling, R-Texas, took himself out of the running Thursday.

"After prayerful reflection, I have come to the conclusion that this is not the right office at the right time for me and my family," he said. Hensarling could be a contender when leadership elections occur again after the vote in November.

Majority Whip Kevin McCarthy, R-Calif., is on track to become the next majority leader despite a challenge from Rules Chairman Pete Sessions, R-Texas, who declared his intention to run Wednesday. Cantor publicly endorsed McCarthy for the job after announcing that he would vacate the position at the end of July.

House Speaker John Boehner, R-Ohio, declined to play favorites, saying, "I do think that the members are going to make this decision." He added, "I've worked with all 434 other members of Congress before. I can work with whoever gets elected."

McCarthy's run for majority leader leaves his whip spot up for grabs. Chief Deputy Whip Peter Roskam, R-Ill., and Rep. Steve Scalise, R-La., who runs a conservative faction of lawmakers in the Republican Study Committee, are vying for that job. Rep. Marlin Stutzman, R-Ind., declared his candidacy for whip Thursday.

Stutzman has voiced the concern that leadership needs more "red state conservatives." Roskam hails from Democratic Illinois. "I'm just getting started," Stutzman told an Indiana politics blog. "There will be a lot happening in the next few days," he said.

House Republicans will vote on their new leadership slate June 19. The quick turnaround is intended to head off divisive campaigns within the raucous GOP rank-and-file. "This is a time for unity," Boehner said Thursday.

Some lawmakers, including GOP Reps. Steve King of Iowa and Michele Bachmann of Minnesota, want to delay the elections to rally more conservative candidates, particularly lawmakers who oppose an overhaul of the nation's immigration laws.

GOP leaders are unlikely to heed that call. In a statement, King said the one-week notice "has the effect of stacking the deck."

Republicans debate what caused Cantor's Virginia primary loss to economics professor Dave Brat, who ran to his right in the race and won by 10 percentage points. Americans for a Conservative Direction, a conservative outfit that supports a comprehensive immigration overhaul, commissioned a poll in Cantor's district of 400 voters who cast ballots in Tuesday's primary.

Nearly eight in ten, 77%, said immigration was not their chief motivating issue, while 22% did. Among Brat's supporters, the notion that Cantor "was too focused on national politics instead of local needs" and "lost touch with voters" fueled their opposition.

Despite Cantor's defeat, Republicans are likely to hold his seat and the House will probably stay under GOP control in the midterm elections. Minority Leader Nancy Pelosi, D-Calif., took issue with that conventional wisdom, arguing that Cantor's upset has focused the nation on what's happening inside the gridlocked U.S. Capitol.

"It's a whole new ballgame, because now the public is paying attention to what is going on here. And what is going on here is the Republican Party is going even further to the right," Pelosi said.